add a parameter for space_subsize_self_grav, gravity self-interactions on...

add a parameter for space_subsize_self_grav, gravity self-interactions on cells with more than this number of particles will be split up.

src/space.c

@@ -62,6 +62,7 @@
 int space_splitsize = space_splitsize_default;
 int space_subsize_pair = space_subsize_pair_default;
 int space_subsize_self = space_subsize_self_default;
+int space_subsize_self_grav = space_subsize_self_grav_default;
 int space_maxsize = space_maxsize_default;
 
 /**
@@ -2701,6 +2702,8 @@ void space_init(struct space *s, const struct swift_params *params,
       params, "Scheduler:cell_sub_size_pair", space_subsize_pair_default);
   space_subsize_self = parser_get_opt_param_int(
       params, "Scheduler:cell_sub_size_self", space_subsize_self_default);
+  space_subsize_self_grav = parser_get_opt_param_int(
+      params, "Scheduler:cell_sub_size_self_grav", space_subsize_self_grav_default);
   space_splitsize = parser_get_opt_param_int(
       params, "Scheduler:cell_split_size", space_splitsize_default);
 

src/space.h

@@ -45,6 +45,7 @@ struct cell;
 #define space_maxsize_default 8000000
 #define space_subsize_pair_default 256000000
 #define space_subsize_self_default 32000
+#define space_subsize_self_grav_default 32000
 #define space_max_top_level_cells_default 12
 #define space_stretch 1.10f
 #define space_maxreldx 0.1f
@@ -57,6 +58,7 @@ extern int space_splitsize;
 extern int space_maxsize;
 extern int space_subsize_pair;
 extern int space_subsize_self;
+extern int space_subsize_self_grav;
 
 /**
  * @brief The space in which the cells and particles reside.